Explosive cutting techniques, methods, and mechanisms are commonly employed in conjunction with space vehicles having vehicle skins or shells which are generally made of aluminum or high strength-to-weight composite materials. Applications of such cutting mechanisms include, among others, missile stage separation and payload release, and missile destruction systems.
A common explosive cutting technique includes the employment of linear shaped charges as particularly shown in U.S. Pat. No. 4,430,939, entitled, "Linear Shaped Charges," issued to G. Harold. Linear shaped charges, commonly employed in missile applications, include a linear V-shaped formed charge which is clad with a light weight metallic material. The explosive physical mechanics of such V-shaped linear charges are particularly described in U.S. Pat. No. 4,649,824, entitled, "Apparatus For Aerospace Vehicle Separation Events Using A Linear Shaped Charge," issued to R. H. Guay.
Another application of a V-shaped linear shaped charge is an explosive cutting device for severing a chain as taught in U.S. Pat. No. 4,148,257, entitled, "Explosive Cutting Device," issued to Orrill, et al. Orrill, et al, teaches the employment of a V-shaped linear charge in combination with a standoff separating the notch of the V-shape charge away from the link of a chain intended to be severed. A similar standoff or separation requirement of the V-shaped charge relative to the surface member intended to be cut is well known, as is also taught in the aforesaid U.S. Pat. No. 4,649,824. The separation distance between the V-shaped charge and the surface intended to be cut is thought to allow the development of a powerful jet of liner material to be propelled toward the target.
One disadvantage of missile severance devices employing linear shaped charges is the difficulty in severing thick walls forming the skin of a missile or vehicle body having a small diameter aperture while at the same time limiting the size of the missile severance device. This is particularly true with increasing volume constraints in smaller type missiles. For example, many types of prior art missile severance devices are not useful for reliably severing missile sections having a diameter of less than about 8 inches with a skin thickness of about 0.75 inches or thicker.
Furthermore, as the size of such missile severance devices employing linear shaped charges decreases, reliability of the missile severance device also decreases.